Biodegradable adhesive

Throughout the 1990s a large portion of the research and development effort for hot melt adhesives focused on developing adhesives that are either environmentally friendly or functional [69,81,82]. Environmentally friendly attributes include biodegradability, water dispersibility (repulpability), renewability, and water releasability. Biodegradable adhesives have been developed based on starch esters [83-86] and polyesters such as poly (hydroxy butyrate/hydroxy valerate) [87], poly(lactide) [88-91], and poly(hydroxy ether esters) [92-94]. All but the... 

In the lamination process, films of different materials are bonded using heat and/ or biodegradable adhesives [23, 34]. A metallized film (e.g., from PLA) with high barrier and stiffness can also be laminated on a Ecoflex /starch or Ecovio compound with good welding performance to produce e.g., a stand pouch for detergents. 

H. Kinoshita, K. Kaizu, M. Fukuda, H. Tokunaga, K. Koga and K. Ikeda, Development of green composite consists of woodchips, bamboo fibers and biodegradable adhesive . Composites Part B Eng, 2009,40, 607-12. 

A surgeon wishes to repair a hernia with a biodegradable adhesive instead of normal sutures. The tension of the skin at the lesion is 290 N m If the total surface area to be bound is 4 cm, what must be the minimum adhesive strength of the bond to ensure a safe closure ... 

One of the unmet clinical needs of orthopedic trauma surgeons is a bone glue or an adhesive to fix a broken bone instead of the conventional metal plates, nails, pins, and screws. Simplicity, quickness, and preservation of joint function, especially when fixing fractures with many small fragments, are the main benefits of a bone adhesive. An additional benefit is elimination of metal removal from fractures fixed solely with a biodegradable adhesive. 

As previously mentioned, some urethanes can biodegrade easily by hydrolysis, while others are very resistant to hydrolysis. The purpose of this section is to provide some guidelines to aid the scientist in designing the desired hydrolytic stability of the urethane adhesive. For hydrolysis of a urethane to occur, water must diffuse into the bulk polymer, followed by hydrolysis of the weak link within the urethane adhesive. The two most common sites of attack are the urethane soft segment (polyol) and/or the urethane linkages. Urethanes made from PPG polyols, PTMEG, and poly(butadiene) polyols all have a backbone inherently resistant to hydrolysis. They are usually the first choice for adhesives that will be exposed to moisture. Polyester polyols and polycarbonates may be prone to hydrolytic attack, but this problem can be controlled to some degree by the proper choice of polyol. 

Despite the universal use of sutures for wound closure, there is a need to utilize adhesives instead, because of their ease of use and the reduced risk of infection. Alkyl cyanoacrylate adhesives have been studied extensively for this use, and a significant amount of research has been performed to evaluate their interaction with living tissue [40,41 J. They have been approved for external use only, because of concerns with the fact that the polymers do not readily biodegrade and can cause inflammation around the area to which it was applied. However, these concerns are reduced for -butyl cyanoacrylate, as compared to the ethyl cyanoacrylate. There is even some evidence that their use as liquid sutures actually reduces the rate of infection around the healing wound or surgical incision [42J. 

Substances which function as tissue adhesives have the unique ability to remain in contact with tissues in localized areas for prolonged periods of time. Not only does the tissue adhesive function as a glue but it has the capacity to serve as a slow release mechanism for drug delivery as it is biodegraded. 

Kwon K, Kidoaki S, and Matsuda T. Electrospun nano- to microfiber fabrics made of biodegradable copolyesters Structural characteristics, mechanical properties and cell adhesion potential. Biomaterials, 2005, 26, 3929-3939. 

Hot melt adhesives based on poly(3HB-co-3HV) have also been described [119]. Hot melts are commonly used in bookbinding, bag ending and case and carton sealing and are mostly based on synthetic materials such as polyethylene, polypropylene ethylene-vinyl acetate and styrene block copolymers [119]. Hot melts based on PHAs alleviate the dependence on petroleum based materials and allow the development of biodegradable alternatives based on natural raw materials. 

A product is only considered to be totally biodegradable if all its single components can be degraded naturally. Currently, pressure sensitive adhesives (PSA) are mostly based on non-biodegradable synthetic polymers such as polyacrylates, ethylene-vinyl acetate copolymers and styrene block copolymers [124]. Therefore there is a growing demand for the application of biodegradable PSAs on naturally degradable products like paper and cardboard. 

PSA compositions must have a good balance of different properties, depending on its specific application. PSAs for adhesive tapes for instance, must have a good adhesion, cohesion, stretchiness and elasticity. Furthermore the base polymers must be elastomers at room temperature [124]. Due to its elastomeric behavior and biodegradability, poly(HAMCL) seems to be a promising base polymer for the development of a completely biodegradable PSA. 

Di-n-butyl phthalate (DBP) Diethyl phthalate (DEP) Butyl benzyl phthalate (BBP) Di(2-ethylhexyl) phthalate (DEHP) a a O O y Plasticizers in PVC production. Component in the manufacture of cosmetics, inks, and adhesives - SW levels are near to 10 pg L 1 in rivers, between 0.5-1 pg L 1 and in sea water between 0.005-0.7 pg L-1 - US streams 2.5 pg L 1 (DEHP) and 0.25 pg L"1 (DEP) [4] Fast biodegradation under aerobic conditions. Half-life in water 1-15 days Half-life in soils 7 days -several months [65]... 

Poly(dichlorophosphazene), 19 56 Polydicyclopentadiene, 8 231 20 432, 433 manufacture of, 20 430 properties of, 20 4221 Polydicyclopentadiene, 26 946-947 Polydime thy lsilane (PDMS). See also Polydimethylsiloxane entries biodegradability of, 22 604-605 lotus effect in, 22 123 pressure-sensitive adhesives and,... 

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